Hydraulic driven air pump



Oct. 6,'1942. B, G, CARLSON i 2,298,106'

HYDRAULIC DRIVEN AIR PUMP Filed April 2'7, 1942 2 Sheets-Sheet 2 IN V EN TOR. .55er Cbasa/v. B

A TTOENEX Patented Oct. 6v, 1942 UNITED sTATEs PATENT OFFICE HYDRAULIC DRIVEN AIR PUMP Bert G. Carlson, Erieside, Ohio, assigner to Jack & Heintz, Inc.,

Cleveland,

Ohio

Application April 27, 1942, Serial No. 440,655

2 Claims.

It is a primary object to provide such a pump l and more particularly a new and novel hydraulic motor and air pump that will preferably be a selfcontained and closed system and which may utilize the lubrication oil of the aircraft engine under pressure as the force for driving the hydraulic pump.

It is a further object to provide a new and novel air pump which will constitute a complementary part of a compact pump unit but which will be readily removable and replaceable with respect to the hydraulic part of the assembly.

l With the foregoing and other objects in view, the invention resides in the combination of parts and in the details of construction hereinafter set forth in the following specication and appended claims, certain embodiments thereof being illustrated in the accompanying drawings in which:

Figure l is a view in vertical section taken through the motor assembly showing the hydraulic pump andair pump and the operative connection therebetween and showing the motor assembly at the completion of 'its down stroke;

Figure 2 is a view similar to Figure 1, showing the pump assembly at the completion of the up stroke; and

Figure 3 is a view in section taken on the line 3-3 of Figure 1.

Referring more particularly to the drawings, the hydraulic motor piston ring lat |2 and keyed thereto at I3. The casing for the hydraulic motor be described is shown at I1 and is provided ywith a. cap I8 which is releasably secured by means of bolts I9. In communication with and adjacent to the main cylinder is an auxiliary cylinder 20 in'which is arranged for vertical reciprocation a i piston whose rod is shown at 2|. This rod has an extension 22 that extends slidably through plate I5 and is provided with a compression coil spring 23 confined between the plate -|5 and a nut 24 above the plate and also a compression spring 25 arranged below the plate I5 to be confined between the same and an auxiliary piston 26.

The oil from some source, such as an engine of the aircraft carrying the automatic pilot, is forced i under pressure into the hydraulic motor through an inlet 21. lAs shown in Figure 1 the hydraulic pistons I and 2 are in the down position, or in other words, at completion of the down stroke. In this position an auxiliary piston 26, carried by rod 2|, has closed the outlet from the pressure -chamber 28 above the upper piston 2 to the'outlet 29 into the passage 30 to the outlet 3| leading to the sump. Likewise, inasmuch as the down stroke has been completed there is no further necessity for drawing in oil under pressure to the top side of the lower piston Therefore the passageway from the inlet 21 to the pressure chamber 32 above order to initiate and continue the up stroke of the piston assembly, communication between the inlet 21 and the chamber 28 below the upper piston 2 urged to the left means of a spring urged to the left means of a spring as shown in Figures l and 2 by detent in the form of a ball 36 as shown in Figures 1 and 2 by 31 a compression of which is adjustably maintained by means of a screw bolt 38 contained in a screw threaded cap 39. The auxiliary piston rod 26 is provided with two bevel shaped respring 23.

the upper piston in chamber hausted, there is no further necessity for any oil to be delivered to this chamber and accordingly the auxiliary piston 33 has closed the ilow o! oil from the inlet 21 to chamber 28. However, inasmuch as delivery of oil under pressure into the pressure chamber 32 above the lower main piston I is essential in order to initiate and complete the down stroke of the main piston assembly, the position of auxiliary piston 33 shown in Fig. 2 permits the flow of oil under pressure from the inlet 21 and through the passage 42 into chamber 32. The continued flow oi such oil under pressure forces the lower main piston I and consequently the main pistonassembly downwardly and this continues against the resilient action of 'Ihis spring 23 maintains they auxiliary pistons 26 and 33 in the position shown in Fig. 2 for regulating the iiow of oil into and out of the main cylinder pressure chambers and until the compression force of spring 26 overcomes that of detent spring 31. This occurs at the completion of the down stroke at which time the detent ball 35 snaps over from its engagement with recess 4I into recess 46 of the auxiliary piston rod in position as shown in Fig. 1.

The foregoing has to do with main essentials of the hydraulic motor .and there will now be described in detail the air pump and its connection with the hydraulic motor. As shown in Figures 1 and 2 the air pump may comprise a casting 43 releasably secured by screw bolts 44 to the casing l1 of the hydraulic motor. As a complementary part of the air pump there is also provided a lower casting 45 secured to the upper casting 43 by means oi screw bolts 46 in such a manner as to provide an air chamber 41 therebetween. The lower portion of the main piston rod 4 extends through a stulng box 48 secured in place by screw bolts 49 the air pump and carries at its lower end a diaphragm 50 which is secured thereto by mean of a nut l and a washer 55 engaging a shoulder of the piston rod. This diaphragm 58 engages a bead 52 oi a resilient suspending member 53 which also has a bead 54 iltting in complementary grooves of the upper and lower castings 48 and proper position by the tightening of the screw bolts 46. It will be readily underforegoing that an upward and downward movement of the main piston rod 4 correspondingly carries the air pump diaphragm 50 downwardly and upwardly into the positions shown in Figures 1 and 2, respectively.

The air pump is provided with a main inlet 56 and outlet 51. Generally speaking, the casting 45 is provided with an air inlet 58 to the upper sideand an inlet 59 to the lower side of the diaphragm and an air outlet 56 from the upper side and an outlet 6| from the lower side of the diaphragm. For the inlet passage- 58 there is provided a cylinder 62 that is secured to the diaphragm 50 so as to be slidable vertically in through the upper casting 43 ofV position shown the casing 45. Referring to Figure 3, the' diaphragm 56 also has formed therein a plurality of retaining fingers 63 for retaining a floating disk 64 in engagement with ,the upper extremity of the cylinder 62 to perform the function or a check valve for permitting air to be drawn upwardly through the cylinder 52 into the chamber 41 above the diaphragm under pressure and prevent its escape through the passageway 68. In order to provide for intake of air through the passage 59 to the underside of the diaphragm a similar cylinder 65 is provided and an identical arrangement ot fingers 53 and floating disk 64 to act as a check valve so as to allow intake of air under pressure to the lower side of the diaphragm and prevent its escape through the passageway 59. On the exhaust side of the air pump and for exhaust of the air from the upper and lower side of the diaphragm through the passageways 60 and4 6I, respectively, there are provided cylinders 65 and 68. In the case oi cylinder 66 the floating disk 64, arranged within the diaphragm, closes the port 81 from the chamber 41 above the diaphragm when it is urged upwardly to close the port 61 in the diaphragm. When the disk 64 is resting on the top of the cylinder 66, as shown in Figure 1, air is free to escape through the port 61 and around the disk 64 through suitable slots near the upper extremity of cylinder 66 so that the air is free to escape through the passageway 50 and out oi the casing outlet 51. In the case o! cylinder 68 a similar iloating disk 54 is provided so as to close a port 69 to prevent escape of air from the underside oi the diaphragm through the outlet 6I. In the in Fig. 1 where the oating disk is resting on the top of cylinder 68 air is free to escape through the port 69 and into suitable slots in the cylinder 68 through the passageway 6l and out through 'the outlet 51.

As mentioned, vFigure the hydraulic motor and the air pump at the completion of the down stroke and shows the position of the air intake and exhaust valves in readiness for initiation of the up stroke to draw air into the air chamber both above and below the diaphragm 56. It that when the diaphragm is drawn upwardly the floating disks 64 on the cylinders 62 and 65 will permit the inrushof air into the air chamber 41 both above and below the diaphragm. It will also be seen that during this up diaphragm any tendency on the part of air to enter the chamber 41 either above or below the diaphragm will be prevented by the automatic setting of disk 54 with the ports 61 and 69, respectively, in the diaphragm. Likewise, during the down stroke of the air pump assembly from its position shown in Figure 2, which represents thefull upstroke position, downwardly to its full down stroke position, shown in Figure 1, any tendency for intake of air under pressure through the passageways 58 o r 59, either above or below the diaphragm, respectively, will be avoided by a setting of disk 64 on the upper ends of cylinders 52 and 65, respectively.

From the foregoing it will be seen that there has been,provided a fully closed and compact hydraulic motor assembly which may readily utilize an hydraulic force of the pressure lubrication system of an engine of an aircraft carrying the automatic pilot or other device to be actua-Led. It will also be seen that there has been provided a compact complementary air pump unit that may be readily and replaceably 1 shows the position of.

will be readily understood secured to the hydraulic motor unit so as to be operated thereby for furnishing air under pressure to a point where it may be available for use as a prime mover for such devices as an air spun gyro that may be used for instance in connection with an automatic fpilot.

I claim:

1. In an air pump having an air chamber and an inlet and outlet, a diaphragm and check valve means for said inlet and outlet, means for reciprocating said diaphragm in said air chamber, said check valve means comprising cylinders with caged oating discs and being carried by said diaphragm so as to shut oil the entrance of air through said vinlet into said air chamber both l' above and below said diaphragm during the exhaust stroke of said diaphragm and shut oil the entry of air into said air chamber both above and below said diaphragm through said outlet during the intake stroke of said diaphragm.

2. In an air pump having an air chamber and an inlet and outlet. a. diaphragm and check valve means for said inlet and outlet, means for operating said diaphragm within said chamber, said check valve means being carried by said diaphragm so as to shut off the entrance of air through said inlet into said air chamber both above and below said diaphragm during the exhaust stroke of said diaphragm and shut oi the entry of air into said air chamber both above and below said diaphragm through said outlet during the intake stroke of said diaphragm.

BERT G. CARLSON. 

